The only purpose of Karl Berry's naming scheme is to support
old-fashioned operating systems.
For the record, that was indeed the original and principal purpose. But
it has turned out not to be the only purpose. Some people like to have
font file names that follow a regular and defined scheme, as opposed to
the (essentially, sometimes completely) random names used by vendors.
And fontinst, as I understand it, will do some things for you if the
fontname naming scheme is followed.
Of course, I don't argue for it strenously myself (and never have,
despite it somehow being "my" naming scheme). It's just a choice that's
out there.
(This has nothing to do with sinuhe's question, of course.)